High Mismatch Research Articles

Microdistortions, Hardness, and Young’s Modulus of Multicomponent Bcc Solid Solutions

The phase composition, type II microstresses, and coherent scattering domains (CSDs) of multicomponent (medium- and high-entropy) bcc solid solutions with an average electron concentration, Csd, ranging from 4.6 to 5.47 e/a were studied. The effect of these characteristics on the hardness and Young’s modulus was analyzed. The alloys were melted in a MIFI-9 vacuum arc furnace using components with a purity of at least 99.5 wt.%; the ingots were remelted six times. The hardness and Young’s modulus of the alloys were determined from nanoindentation curves plotted with a Micron Gamma unit under a load from 0.98 to 2.94 N using a Berkovich diamond pyramid under automated loading and unloading. A relatively small change in the quantitative chemical composition of the samples led to a noticeable change in the lattice parameter, type II microstresses, CSDs, microhardness, and Young’s modulus. The greatest possible type II microstresses and minimum CSD sizes were observed for the alloys characterized by high average mismatch between the atomic sizes of their constituent elements. Increase in the electron concentration in the alloys led to higher hardness and Young’s modulus and lower lattice parameter. Increase in the type II microstresses was also accompanied by higher hardness and Young’s modulus. The microhardness H of alloys significantly exceeded that calculated with the mixture rule, Hmix, and was determined by solid-solution hardening (∆H = H – Hmix ranging between 2.9 and 6.4 GPa). Type II microstresses precisely calculated from the X-ray line width can be used for measuring the distortion of the solidsolution lattice and assessing solid-solution hardening. The relationship between the magnitude of solid-solution hardening, Young’s modulus, and lattice microdistortions (type II microstresses) was proposed.

Predictive factors in the treatment of oral squamous cell carcinoma using PD-1/PD-L1 inhibitors.

Due to immune impairment and lymphocyte enrichment of oral squamous cell carcinoma (OSCC), anti-PD-1/PD-L1 therapy is regarded as a potential treatment option. However, tumor heterogeneity, differences in the immune conditions of patients, and the interrelation between tumor cells and stromal cells within the tumor microenvironment (TME) could affect the therapeutic efficacy of immune checkpoint blockades. Therefore, to maximize the benefit of blockade PD-1/PD-L1 axis, to find an efficient predictor (the possible clinical parameters or biological factors) before treatment are of great importance. In this review, we discuss the advantages of anti-PD-1/PD-L1 therapy for OSCC patients and find three respects that are currently available in predicting curative effect. Firstly, OSCC with high PD-L1 expression evaluating by immunohistochemistry (high tumor proportion score (TPS) and combined positive score (CPS)) are considered to be suitable for anti-PD-1/PD-L1 therapy. Secondly, gene-level predictive biomarkers including high metastatic mismatch repair deficiency (dMMR) signature or enrichment of interferon-γ and PD1 signaling pathway is expected to be favorable factors. Besides, PET/CT parameters (SUVmax, MTV, TLG) are proved to be correlated with PD-L1 expression, and some newly developed immunoPET probes are enlarging the application of PET/CT in predicting therapeutic efficacy of PD-1/PD-L1 inhibitors.

High‐strength medium‐entropy (Ti,Zr,Hf)C ceramics up to 1800°C

AbstractMedium‐entropy (Ti,Zr,Hf)C ceramics were prepared by hot pressing a dual‐phase medium‐entropy carbide powder with low oxygen content (0.45 wt%). The results demonstrate that the medium‐entropy (Ti,Zr,Hf)C ceramics sintered at 2100°C had a relative density of 99.2% and an average grain size of 1.9 ± 0.6 μm. The flexural strength of (Ti,Zr,Hf)C carbide ceramics at room temperature was 579 ± 62 MPa. With an increase in temperature to 1600°C, the flexural strength showed an increase up to 619 ± 57 MPa, and had no significant degradation even up to 1800°C. The high‐temperature flexural strengths of (Ti,Zr,Hf)C were obviously higher than those of the monocarbide ceramics (TiC, ZrC, and HfC). The primary strengthening mechanism in (Ti,Zr,Hf)C could be attributed to the high lattice parameter mismatch effects between TiC and ZrC, which not only inhibited the fast grain coarsening of (Ti,Zr,Hf)C ceramics, but also increased the grain‐boundary strength of the obtained ceramics.

Absorption-dominant radio-wave attenuation loss of metals and graphite

Absorption-dominant radio-wave (0.2–2.0 GHz) attenuation loss is comparatively reported for materials of high electrical conductivity, namely metals (aluminum and steel) and graphite. These materials exhibit similarly high absorption loss (≤ 91.5%) and similarly low reflection loss (≥ 8.5%), both as fractions of the total loss in dB. The absorption loss is high (< 55 dB) and the reflection loss is low (< 10 dB) for both graphite and the metals. The absorption-dominant attenuation loss of these high-conductivity materials is in contrast to the notion that high conductivity (due to the high impedance mismatch with air) generally causes reflection-dominant attenuation loss. The metals and graphite are in foil form, with the graphite being thicker than the metals. The linear absorption coefficient (directly related to the absorption loss per unit thickness) is lower for graphite (≤ 93 mm−1) than the metals (≤ 394 mm−1), due to the greater thickness of the graphite. The absorption loss and fractional absorption loss contribution increase with increasing frequency, whereas the reflection loss decreases, as consistent with electromagnetic theory. On the other hand, from the viewpoint of the fractional loss in power, reflection dominates over absorption for all three materials in the entire frequency range. For shielding, the metals are more effective than graphite if the absorption loss per unit thickness (< 3400 dB/mm) is considered. For stealth, graphite is advantageous to the metals in the low reflection loss, though it is disadvantageous in the low absorption loss per unit thickness.

Evidence for strain control of magnetic anisotropy in epitaxial nickel ferrite thin films grown on strontium titanate substrates

This report is on strain control of magnetic order parameters in 50 nm epitaxial NiFe2O4 (NFO) films grown on (001), (110), and (111) SrTiO3 (STO) single-crystal substrates by pulsed laser deposition. The related in-plane strains for NFO films on (001), (110), and (111) STO substrates are found to be ―1.36 %, 1.35 %, and 1.52 %, respectively, where the lattice mismatch between film and substrate is as high as 6.7 %. Our analysis of magnetization and ferromagnetic resonance on all the NFO films reveals the presence of a uniaxial anisotropy field, which is perpendicular to the film plane. The anisotropy field decreases with the increase of strain in NFO films. Specifically, NFO films on STO (111) and STO (001) have the lowest and highest uniaxial anisotropy fileds of 1.4 kOe and 6.1 kOe, respectively. These experimental values of anisotropy field are a factor of 5–10 times smaller than those of the calculated ones due to the film defects induced by the high lattice mismatch. The studies of magnetic anisotropy of spinel ferrite films are of interest for spintronics and microwave devices.

Patient and provider perception of appropriateness, acceptability, and feasibility of behavioral health home (BHH) core components based on program implementation in an urban, safety-net health system.

This manuscript evaluates patient and provider perspectives on the core components of a Behavioral Health Home (BHH) implemented in an urban, safety-net health system. The BHH integrated primary care and wellness services (e.g., on-site Nurse Practitioner and Care Manager, wellness groups and tools, population health management) into an existing outpatient clinic for people with serious mental illness (SMI). As the qualitative component of a Hybrid Type I effectiveness-implementation study, semi-structured interviews were conducted with providers and patients 6 months after program implementation, and responses were analyzed using thematic analysis. Valence coding (i.e., positive vs. negative acceptability) was also used to rate interviewees' transcriptions with respect to their feedback of the appropriateness, acceptability, and feasibility/sustainability of 9 well-described and desirable Integrated Behavioral Health Core components (seven from prior literature and two additional components developed for this intervention). Themes from the thematic analysis were then mapped and organized by each of the 9 components and the degree to which these themes explain valence ratings by component. Responses about the team-based approach and universal screening for health conditions had the most positive valence across appropriateness, acceptability, and feasibility/sustainability by both providers and patients. Areas of especially high mismatch between perceived provider appropriateness and measures of acceptability and feasibility/sustainability included population health management and use of evidence-based clinical models to improve physical wellness where patient engagement in specific activities and tools varied. Social and peer support was highly valued by patients while incorporating patient voice was also found to be challenging. Findings reveal component-specific challenges regarding the acceptability, feasibility, and sustainability of specific components. These findings may partly explain mixed results from BHH models studied thus far in the peer-reviewed literature and may help provide concrete data for providers to improve BHH program implementation in clinical settings. Many people with serious mental illness also have medical problems, which are made worse by lack of access to primary care. The Behavioral Health Home (BHH) model seeks to address this by adding primary care access into existing interdisciplinary mental health clinics. As these models are implemented with increasing frequency nationwide and a growing body of research continues to assess their health impacts, it is crucial to examine patient and provider experiences of BHH implementation to understand how implementation factors may contribute to clinical effectiveness. This study examines provider and patient perspectives of acceptability, appropriateness, and feasibility/sustainability of BHH model components at 6-7 months after program implementation at an urban, safety-net health system. The team-based approach of the BHH was perceived to be highly acceptable and appropriate. Although providers found certain BHH components to be highly appropriate in theory (e.g., population-level health management), their acceptability of these approaches as implemented in practice was not as high, and their feedback provides suggestions for model improvements at this and other health systems. Similarly, social and peer support was found to be highly appropriate by both providers and patients, but in practice, at months 6-7, the BHH studied had not yet developed a process of engaging patients in ongoing program operations that was highly acceptable by providers and patients alike. We provide these data on each specific BHH model component, which will be useful to improving implementation in clinical settings of BHH programs that share some or all of these program components.

Ice nucleation activity of iron oxides via immersion freezing and an examination of the high ice nucleation activity of FeO.

Heterogeneous ice nucleation is a common process in the atmosphere, but relatively little is known about the role of different surface characteristics on the promotion of ice nucleation. We have used a series of iron oxides as a model system to study the role of lattice mismatch and defects induced by milling on ice nucleation activity. The iron oxides include wüstite (FeO), hematite (Fe2O3), magnetite (Fe3O4), and goethite (FeOOH). The iron oxides were characterized by X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface area measurements. The immersion freezing experiments were performed using an environmental chamber. Wüstite (FeO) had the highest ice nucleation activity, which we attribute to its low lattice mismatch with hexagonal ice and the exposure of Fe-OH after milling. A comparison study of MnO and wüstite (FeO) with milled and sieved samples for each suggests that physical defects alone result in only a slight increase in ice nucleation activity. Despite differences in the molecular formula and surface groups, hematite (Fe2O3), magnetite (Fe3O4), and goethite (FeOOH) had similar ice nucleation activities, which may be attributed to their high lattice mismatch to hexagonal ice. This study provides further insight into the characteristics of a good heterogeneous ice nucleus and, more generally, helps to elucidate the interactions between aerosol particles and ice particles in clouds.

Multidisciplinary approach for improvement of immunotherapy utilization in solid tumors with H MSI /dMMR –An action plan from a single oncology center

Immune checkpoint inhibitors such as nivolumab and pembrolizumab are approved by Food and Drug Administration for patients diagnosed with metastatic solid tumors with high microsatellite instability (MSI) or mismatch repair deficient (dMMR). The prognosis of these patients is generally poor, that is why it is very essential to identify the targeted patients who can benefit from immunotherapy. Pembrolizumab is approved in our institution for this indication. In order to ensure proper utilization of available resources, we decided to make a pilot retrospective review to evaluate pembrolizumab utilization, to identify the problems we are facing then to set an action plan through multidisciplinary approach. Based on the results we set recommendations. This paper is innovative and the first in kind. It could be used as guidance for other centers using immunotherapy and could be applied for other drugs as well to ensure best practice, patient safety and maximize utilization of resources.

Application of Immune Checkpoint Inhibitors in the Treatment of Cholangiocarcinoma

Cholangiocarcinoma is a general term for intrahepatic and extrahepatic malignant tumors deriving in the biliary system. According to the location, it is divided into intrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, and distal cholangiocarcinoma. Progressive cholangiocarcinoma yields poor outcomes with radiotherapy; therefore, there is an urgent need for new therapeutic breakthroughs. Immune checkpoint inhibitor (ICI) therapy brings the treatment for cancer into a new field, with the use of drugs targeting PD-1/PD-L1 and CTLA-4 considerably extending the survival of patients with melanoma, lung cancer, and other solid tumors. The FDA has approved the application of pembrolizumab for solid tumors with high microsatellite instability and defective mismatch repair, including cholangiocarcinoma. Moreover, the combination of ICIs with chemotherapy and radiation therapy showed good promise. The aim of the present study was to review the application of ICIs in the treatment of cholangiocarcinoma and to summarize the reported individualized immunotherapy-based protocols and ongoing clinical trials for clinical reference.

Fault Detection and Classification for Photovoltaic Systems Based on Hierarchical Classification and Machine Learning Technique

Line-line (LL) and line-ground (LG) faults may not be detected by common protection devices in Photovoltaic (PV) arrays as these faults are not detectable under high fault impedance and low mismatch level. In recent years, many efforts have been devoted to overcome these challenges using intelligent methods. However, these methods could not classify the type of faults and diagnose their severity. In this article, we propose a novel and intelligent fault monitoring method to detect and classify LL and LG faults at the dc side of PV systems. For this purpose, the main features of current-voltage curves under different fault events and normal conditions are extracted. The faults are categorized using the hierarchical classification platform. Later, the LL and LG faults are detected and classified by machine learning methods. The proposed method aims to reduce the amount of dataset, which is required for the learning process, and also obtains a higher accuracy in detecting and classifying the fault events at low mismatch levels and high fault impedance compared with other fault diagnostic methods. The experimental results verify that the proposed method precisely detects and classifies LL and LG faults on PV systems under different conditions and severity with the accuracy of 96.66% and 91.66%, respectively.

Tunable and sizeable band gaps in strained SiC3/hBN vdW heterostructures: A potential replacement for graphene in future nanoelectronics

In this work, we perform first-principles density functional theory calculations to study siligraphene (SiC3)/hexagonal boron nitride (hBN) vdW-heterostructures. Siligraphene has comparable electronic properties to graphene, including the presence of a Dirac-like cone, thus we investigate its potential as a replacement for graphene. We find that, when internal strains induced by the high lattice mismatch between the SiC3 and hBN layers are reduced, a very small and non-tunable gap is induced in a hybrid bilayer heterostructure. However, the picture becomes quite different when structures with higher internal strains are considered. In this scenario, the compressive strain induces a buckling in the SiC3 sheet, resulting in larger band gaps. Additionally, in many configurations, the gaps are found to be quite tunable by the application of external strains or an electrical field. Such tunability is absent in graphene/hBN heterostructures, thus giving SiC3/hBN heterostructures a clear edge. The origin of this gap and its tunability are discussed in terms of the buckling in the SiC3 layer and the interlayer charge transfer. Finally, the optical properties of these heterostructures were also investigated. Strong absorption peaks in both visible and deep UV regions were found, which could be explored for applications in future optoelectronic devices.

Comparative study of metamorphic InAs layers grown on GaAs and Si for mid-infrared photodetectors

We report a comparative study of metamorphic InAs p-i-n photodetectors epitaxially grown on GaAs and Si by molecular beam epitaxy. Linearly graded InAlAs buffers were employed to bridge the high lattice mismatch between InAs and Si. Quantitative measurement for threading dislocation density (TDD) in the InAs layers grown on GaAs and Si has been performed using transmission electron microscopy and electron channeling contrast imaging, both of which revealed that the TDD of InAs/Si sample is ~35% higher than that of GaAs sample. Comparison of fabricated InAs p-i-n photodetectors indicated that reduction of threading dislocation density is crucial for low dark current and high responsivity mid-infrared photodetectors on Si.

High-Bandwidth Quasi-Circulator-Based Monostatic Automotive Radar With Self-Interference Suppression

We present a novel quasi-circulator (QC)-based monostatic radar MMIC with self-interference suppression. This article concentrates on the proper operation of the radar system, especially in the presence of antenna port mismatch. A relatively high receiver gain of around 28 dB is provided in the RF domain to relax the demand on the IF chain. Thus, antenna port mismatch becomes even more critical as already small levels of TX/RX leakage drive the receiver chain in compression. It can be shown that the measured 14-dB receiver noise figure can be provided even in the presence of a high mismatch. Therefore, detailed analyses according to TX/RX isolation are given based on on-wafer and onboard measurements with different antenna port terminations. In the case of on-wafer measurements, the comparison between on-chip 50- $\Omega $ termination and RF-probe termination is performed. In the case of onboard measurements, the comparison is performed based on a waveguide match, a standard horn antenna, and a high-gain parabolic antenna. Even in the presence of a mismatch of almost 4 dB in the receiver path, the proposed MMIC provides sufficient isolation to avoid any receiver compression effects. Finally, the assessment of the proposed radar MMIC for frequency-modulated continuous-wave (FMCW) application is demonstrated based on an outdoor measurement with a target (7-cm corner reflector) placed in a 100-m distance. Using the parabolic antenna, the SNR of target measurement remains at 25 dB.

Concentrating solar thermal desalination: Performance limitation analysis and possible pathways for improvement

Solar thermal desalination is a viable approach for sustainable water production. Current thermal desalination technologies suffer from high specific energy consumption and energy mismatch. Concentrating solar collectors operate with high temperature energy and desalination systems operate with low temperature energy which leads to large exergy destruction. Herein, a thermodynamic model of an ideal concentrating solar-distillation process is developed to evaluate system integration and performance limitations (specific water production). Three different heating architectures are examined to understand how solar collector absorber temperature, concentration ratio, and recovery ratio impact system performance. A reversible solar distillation system operating with a concentration ratio of 10 at the optimal absorber temperature of 507 K can achieve a maximum specific water production of ~166.3 gs−1m−2 as the recovery ratio (rr) approaches zero. An endo-reversible heat engine model was formulated to consider system irreversibilities. Systems with irreversibilities (R = 0.001 K/kW or 0.005 K/kW) experience a decrease in the water production rate to 8.8 g s−1m−2 (rr = 51.4%) and 1.9 g s−1m−2 (rr = 65.2%). For efficient integration of solar collectors with thermal desalination systems, it is critical to adopt appropriate heating configurations and control absorber temperatures, system recovery ratio, and system irreversibilities.

Microstructure improvement of C/SiC-Nb brazing joints reinforced with heat penetration

Brazing C/SiC composites and Nb is always trouble with high residual stress owing to high property mismatch, especially in terms of the coefficient of thermal expansion. It weakens the joining strength and reduces the joining quality due to welding defects. The traditional method tends to modify the brazing alloy to overcome the problem of property mismatch by introducing reinforcement or interlayer. However, the application of these methods was limited by the low addition and poor distribution, thus inhibiting the development of brazing composites and alloy, as well as the use of composites. An increase in aircraft speed and size requires the composite-alloy joint to exhibit higher joining strength. To achieve this, heat penetration was employed to modify the composite surface of brazing C/SiC and Nb with the AgCuTi brazing alloy. It aims to provide a new idea for the design of the composite-alloy joint. In this study, the microstructure, residual stress distribution, and reinforced mechanism of the joints were investigated in detail. Ni-Cr-Si alloy was introduced to penetrate due to the good reactive diffusion of Ni with SiC. The Ni2Si+C phase was in situ synthesized by replacing the SiC matrix and constructing the penetration zone using carbon fibers. The high strength and elasticity of the carbon fiber dispersed in the penetration zone increase the mechanical properties and decrease the brittleness. Moreover, the wettability of Ni-Cr-Si alloy on C/SiC composites improved as the Cr content increased. The ideal content of penetrating alloy was confirmed as Ni10Si15Cr (wt%). To reduce the brittleness of the composite-alloy joint, such content needs to be removed, so that bonding between alloys can be achieved. The typical microstructure of penetrated joints was C/SiC/Cf+Ni2Si+Cr3Ni2Si+Cr23C6/Ag(s,s)+(Cu,Ni)/Nb. The Cr elements were slightly diffused into the penetrating zone, thus reinforcing the bonding between carbon phases and Ni-Si compounds. The reaction layer of the compounds on C/SiC composites was replaced with the fiber reinforced penetration zone. The depth of this zone directly influenced the joining strength. To investigate in detail the penetration parameters, the penetration depth was optionally and homogeneously controlled. Accurate regulation of the penetration depth is beneficial for various application conditions. In addition, the reinforcing mechanism of penetration focused on the reduction of residual stress and enhancement of the C/SiC-alloy interface. In the penetration zone, the coefficient of thermal expansion gradually changed from C/SiC to AgCuTi alloy, which reduced the residual stress. The stress concentration of the C/SiC interface in the original joint was also eliminated. The fiber bundles supported the residual stress to prevent the appearance of cracks. Consequently, the residual stress in the brazing seam was reduced. The carbon fibers and dispersed phase enhanced the fracture strength and toughness of the penetrating zone. Fracture occurred in the penetration zone rather than in the reaction layer, with breaking and pulling out of fibers. A longer fracture path requires more energy for crack propagation. All these improvements contributed to the joining quality. The average shear strength increased from 85.5 to 115.2 MPa, with a penetrating depth of 77 μm. The penetration treatment of C/SiC composites provides a new method of brazing composites to alloy. Such method is suitable for different brazing alloys and various brazing requirements. Moreover, it enables the surface modification of composites. Thus, it is important to pay attention to the crucial effect of fiber reinforcement on composites. This research aimed to efficiently expand the application of composites and dissimilar joints.

Capturing and Micromechanical Analysis of the Crack-Branching Behavior in Welded Joints

During the crack propagation process, the crack-branching behavior makes fracture more unpredictable. However, compared with the crack-branching behavior that occurs in brittle materials or ductile materials under dynamic loading, the branching behavior has been rarely reported in welded joints under quasi-static loading. Understanding the branching criterion or the mechanism governing the bifurcation of a crack in welded joints is still a challenge. In this work, three kinds of crack-branching models that reflect simplified welded joints were designed, and the aim of the present paper is to find and capture the crack-branching behavior in welded joints and to shed light on its branching mechanism. The results show that as long as there is another large enough propagation trend that is different from the original crack propagation direction, then crack-branching behavior occurs. A high strength mismatch that is induced by both the mechanical properties and dimensions of different regions is the key of crack branching in welded joints. Each crack branching is accompanied by three local high stress concentrations at the crack tip. Three pulling forces that are created by the three local high stress concentrations pull the crack, which propagates along with the directions of stress concentrations. Under the combined action of the three pulling forces, crack branching occurs, and two new cracks initiate from the middle of the pulling forces.

Hukou System, Horizontal, Vertical, and Full Job-Education Mismatch and Wage Progression among College Floating Population in Beijing, China

This article investigates college graduates in Beijing, China, and asks, First: Whether college graduates without local hukou are prone to educational mismatch? Second: What role does the hukou system play in the educational mismatch? And third: Whether college graduates without local hukou are willing to lower their wages in order to get a hukou? I use the Beijing College Students Panel Survey (BCSPS), and multinomial logit models and the linear regression analyses are conducted. I find that college graduates with (without) local hukou through job are more likely to be vertical and full mismatch than locals, and those who obtain a hukou through job have a higher full mismatch. After considering the educational mismatch, there is no significant difference in monthly wages between college graduates (not) having a hukou by work and locals.

Structural, magnetic and dielectric properties in 3d–5d based Sr2FeIrO6 thin films

The structural, magnetic and dielectric properties have been investigated in 3d–5d based double perovskite Sr2FeIrO6 thin films deposited by pulse laser deposition technique. To understand the effect of strain, epitaxial films are grown with varying thickness as well as on different substrates i.e., SrTiO3 (100) and LaAlO3 (100). The films with highest thickness are found to be more relaxed. Atomic force microscope images indicate all films are of good quality where grain sizes increase with increase in film thickness. X-ray absorption (XAS) spectroscopy measurements indicate a Ir5+ charge state in present films while providing a detailed picture of hybridization between Fe/Ir-d and O-p orbitals. The bulk antiferromagnetic transition is retained in films though the transition temperature shifts to higher temperature. Both dielectric constant (ϵ r) and loss (tan δ) show change around the magnetic ordering temperatures of bulk Sr2FeIrO6 indicating a close relation between dielectric and magnetic behaviors. A Maxwell–Wagner type relaxation is found to follow over whole frequency range down to low temperature in present film. On changing the substrate i.e., LaAlO3 (100), the ϵ r(T) and (tan δ(T)) show almost similar behavior but ϵ r shows a higher value which is due to an increased strain coming from high mismatch of lattice parameters.

The relationship between donor-recipient genetic distance and long-term kidney transplant outcome

Background: We set out to quantify shared genetic ancestry between unrelated kidney donor-recipient pairs and test it as a predictor of time to graft failure. Methods: In a homogenous, unrelated, European cohort of deceased-donor kidney transplant pairs (n pairs = 1,808), we calculated, using common genetic variation, shared ancestry at the genic (n loci=40,053) and genomic level. We conducted a sub-analysis focused on transmembrane protein coding genes (n transcripts=8,637) and attempted replication of a previously published nonsynonymous transmembrane mismatch score. Measures of shared genetic ancestry were tested in a survival model against time to death-censored graft failure. Results: Shared ancestry calculated across the human leukocyte antigen (HLA) significantly associated with graft survival in individuals who had a high serological mismatch (n pairs = 186) with those who did not have any HLA mismatches indicating that shared ancestry calculated specific loci can capture known associations with genes impacting graft outcome. None of the other measures of shared ancestry at a genic level, genome-wide scale, transmembrane subset or nonsynonymous transmembrane mismatch score analysis were significant predictors of time to graft failure. Conclusions: In a large unrelated, deceased-donor European ancestry renal transplant cohort, shared donor-recipient genetic ancestry, calculated using common genetic variation, has limited value in predicting transplant outcome both on a genomic scale and at a genic level (other than at the HLA loci).

Contact pressure distribution of the hip joint during closed reduction of developmental dysplasia of the hip: a patient-specific finite element analysis

BackgroundDevelopmental dysplasia of the hip (DDH) is the most common deformity of the lower extremity in children. The biomechanical change during closed reduction (CR) focused on cartilage contact pressure (CCP) has not been studied. Thereby, we try to provide insight into biomechanical factors potentially responsible for the success of CR treatment sand complications by using finite element analysis (FEA) for the first time.MethodsFinite element models of one patient with DDH were established based on the data of MRI scan on which cartilage contact pressure was measured. During CR, CCP between the femoral head and acetabulum in different abduction and flexion angles were tested to estimate the efficacy and potential risk factors of avascular necrosis (AVN) following CR.ResultsA 3D reconstruction by the FEA method was performed on a 16 months of age girl with DDH on the right side. The acetabulum of the involved side showed a long, narrow, and “flat-shaped” deformity, whereas the femoral head was smaller and irregular compared with the contralateral side. With increased abduction angle, the stress of the posterior acetabulum increased significantly, and the stress on the lateral part of the femoral head increased as well. The changes of CCP in the superior acetabulum were not apparent during CR. There were no detectable differences in terms of pressure on the femoral head.ConclusionsSevere dislocation (IHDI grade III and IV) in children showed a high mismatch between the femoral head and acetabulum. Increased abduction angle corresponded with high contact pressure, which might relate to AVN, whereas increased flexion angle was not. Enhanced pressure on the lateral part of the femoral head might increase the risk of AVN.